Travis: Test on more platform and use new travis container

Author: lyrixx

.travis.yml

@@ -1,8 +1,16 @@
 language: php
+
+sudo: false
+
 php:
     - 5.3
     - 5.4
     - 5.5
+    - 5.6
+    - 7
+    - hhvm
+
 script: phpunit
+
 before_script:
     - composer install --dev --prefer-source